A substance obtained by binding functional particles having functionalities such as heat conductivity, electrical conductivity, magnetism, a dielectric property, a gas barrier property and the like by a binder and molding the same is widely known in general.
In the above, however, there has been such a problem that heat insulation or insulation is caused and the characteristics of the functional particles are inhibited if the quantity of the binder is large while flexibility, moldability etc. of an obtained functional molded article are reduced if the quantity of the binder is merely reduced.
In the meantime, there is also known a technique (refer to Patent Literature 1, for example) of blending functional particles into a fibrous substance, while no binder is employed in this technique and hence no inhibition of functionalities by a binder takes place. In a functional molded article obtained in this manner, however, there has been such a problem that the substance is torn or a fall of the functional particles takes place.
As another prior art of the functional molded article, there is known a functional molded article characterized in that functional particles are fixed to a porous body by fibrillated polytetrafluoroethylene (PTFE), although this is a technique different in a point of fixing the functional particles to a substrate consisting of the porous body thereby supplying functionalities from the aforementioned prior art employing no such substrate (refer to Patent Literature 2). According to this technique, it is assumed that a large quantity of functional powder is fixed to the porous body by a three-dimensional network structure of PTFE converted to a fine fibrous substance having adhesiveness due to the fibrillation and hence the whole surface of the functional powder is not covered with PTFE, the functions of the functional powder are not damaged, the functions of the functional powder are sufficiently exhibited with respect to a substance passing through the inner portion of the functional material or coming into contact with the functional material, and the functional powder does not easily fall in production or use of the functional material.
Similarly, there is also known a functional molded article characterized in that functional powder is fixed to a porous body by a mixture consisting of a binder and microfibril cellulose (MFC) as a technique employing a porous body (refer to Patent Literature 3). According to this technique, it is assumed that the functional powder is fixed to the porous body and a fall of the functional powder is reliably prevented due to adhesive force of the binder and bonding force and intertwining force of the microfibril of MFC, while the microfibril of MFC forms a three-dimensional netlike structure, incorporates the powder thereinto and maintains high porosity, and hence the surface of the functional powder is not covered with a film of the binder, and the functions of the functional powder are not damaged.
The aforementioned techniques are techniques of fixing functional particles to porous bodies and essentially employ porous bodies such as unwoven fabric, and hence the functional molded articles in these techniques have been poor in flexibility.
While a binder is common to a fibrous substance described later in a function of capturing functional particles as viewed in the examples of the prior art described above, the term “binder” does not include a fibrous substance in the present invention, after the conventional illustration. Further, a term “capturing material” is employed when generically referring to the two on the basis of common capturing functions of the two.